Edsmall/no data error message
Jira Issue
None, tracked in github:
Python Implementation
If we get no data, the analysis is completely pointless, and is actually more likely to be a sign that the user has set things up incorrectly.
Instead, we halt the process here, and suggest that the user checks that their wmo_boxes are calibrated correctly (the 1 and 0 columns), or to check that file directories are correct.
Testing
Alter not data test to check for a raised error, rather than checking we receive useless data values
Old Matlab Implementation
If we get no data, just return some random data that will be unused